Today, video can be used in increasingly diverse applications with a correspondingly diverse set of client devices, from computers viewing Internet video to mobile phones with mobile television capabilities. The video streams for these devices can vary substantially. To address these requirements, video delivery within Long Term Evolution (LTE) networks often relies on efficient video formats which maximize available bandwidth and appropriately targets the client device. One codec which offers many advantages over traditional encodings is Scalable Video Codec (SVC), an extension of the H.264/MPEG4 Advanced Video Coding.
Conventional approaches to transmit compressed video utilize the available channel rate as the independent entry and impose the source rate by configuring the video compression parameters like frame size, frame rate, constant bitrate, quality factor, etc. This approach can only be implemented if the entity sensing the channel rate can access the compressor parameters. In addition, when direct control is possible the compression can be restarted each time a relevant compression parameter is readjusted. Alternatively, multiple compressors can be operated simultaneously for complying preset channel rates. This alternative necessitates the use of multiple compression equipment, one for each preset rate. In the alternative, the switching between the outputs of different compressors (as a result of channel rate change), necessitates control signaling analogous to the resetting of the compression parameters of a single compressors.
An improved version of this alternative generates fixed duration source streams in multiple versions (each version corresponding to a preset channel rate) such that at the end of the fixed duration (e.g., two seconds) the proper stream can be conveyed to the channel. In this improved version of the alternative, each source bit stream representing a fixed duration of video can have its own starting and ending control signaling. This control signaling consumes a portion of amount of channel resource which is often scarce. This improved alternative also necessitates the use of multiple compressors.